I used to work for a school district and they loved to spend a couple of grands in federal fund money to buy policom equipment.

The only way to get it off to the internet was to put it in the DMZ. Everytime we tried to route it the performance suffered. I hated installing and configuring them and it got used MAYBE twice a year.

To be fair H.323 sucks through NATs and that's not Polycom's fault it's just a shitty standard. The only way to get it to work reliably is to use an H.323 gatekeeper or get a firewall that really understands it, but none of them seem to.